Thermal conductivity of printing material

[dangoo]

I am looking at an additive manufacturing route as an alternative to an existing technology which currently uses machined aluminium for its tooling. The process is thermally cyclic between 65C and room temperature and requires a good level of dimensional accuracy. While the mechanical properties are important to material selection, the focus of this thread is regarding the thermal properties.

When researching possible printing materials, I was surprised to see the thermal conductivity of commercially available printing materials are quite low, between 0.4 - 0.8 W/m-K and the alleged high thermally conductive materials top out at around 4 - 8 W/m-K, in-plane and 1 - 4 W/m-K, through plane (Example:

https://tcpoly.com/wp-content/uploads/2019/10/TDS_Ice9_Rigid_r305.pdf

). Could someone explain why the thermal conductivity isn't higher and what it would take to increase it?

 

[3DDave]

In solids thermal conductivity is high when there is a rigid, typically crystal, structure. Plastics aren't rigid and don't have much in the way of crystals. Electrical conductivity is also related to thermal conductivity; plastics aren't particularly electrically conductive.

Materials like diamond (very rigid, very crystaline) and gold (very electrically conductive) are both very thermally conductive.

Use Google to search for "how to increase thermal conductivity of plastic"